I think this is the hardest part of my Driver 2 Advance modification. What I wish to achieve is to make the game Full Screen, or, if it wouldn't be possible, 16:9 with black bars. I'll try explaining as much as I can.The normal in-game screen.
In-game, there is a part of the screen displaying the raycaster, and the upper part is displaying the UI and Mini-map. Under the UI and the upper half of the mini-map, there is the first tile of the visible raycaster screen repeated ; also, the tiles for the pause menu. Under the lower half of the mini-map, there are hidden Raycaster tiles :
I would like to get rid of the UI (which I can do already) and "add" the missing raycasting tiles in the UI area. Or shift the visible raycaster 2 rows of tiles up and make black bars up and down to make a cinematic effect, if raycasting tiles can't be "added" to complete the upper part.
In the RAM, I could find the adresses where the tiles described above are being injected - these tiles are always changing and updated to display 2 different frames found in the ROM - like an animated drawing while flipping pages. Also, in the ROM, I found the adresses where the visible raycasting tiles are "created" - 1st frame is found from 0806E930 and 2nd frame is found from 0806ED30. It works this way :
What I think I didn't find yet, is the part of the ROM which indicates where to inject the Raycaster into the RAM (what row of tiles). Also, I'm not sure if new tiles can be created to complete the Raycaster under the UI.
So, if someone know about Raycasting on the GBA, I need some help to understand what can be done and how.